xref: /openbmc/qemu/audio/noaudio.c (revision 1fd6bb44)
1 /*
2  * QEMU Timer based audio emulation
3  *
4  * Copyright (c) 2004-2005 Vassili Karpov (malc)
5  *
6  * Permission is hereby granted, free of charge, to any person obtaining a copy
7  * of this software and associated documentation files (the "Software"), to deal
8  * in the Software without restriction, including without limitation the rights
9  * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
10  * copies of the Software, and to permit persons to whom the Software is
11  * furnished to do so, subject to the following conditions:
12  *
13  * The above copyright notice and this permission notice shall be included in
14  * all copies or substantial portions of the Software.
15  *
16  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
17  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
18  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
19  * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
20  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
21  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
22  * THE SOFTWARE.
23  */
24 #include "qemu-common.h"
25 #include "audio.h"
26 #include "qemu/timer.h"
27 
28 #define AUDIO_CAP "noaudio"
29 #include "audio_int.h"
30 
31 typedef struct NoVoiceOut {
32     HWVoiceOut hw;
33     int64_t old_ticks;
34 } NoVoiceOut;
35 
36 typedef struct NoVoiceIn {
37     HWVoiceIn hw;
38     int64_t old_ticks;
39 } NoVoiceIn;
40 
41 static int no_run_out (HWVoiceOut *hw, int live)
42 {
43     NoVoiceOut *no = (NoVoiceOut *) hw;
44     int decr, samples;
45     int64_t now;
46     int64_t ticks;
47     int64_t bytes;
48 
49     now = qemu_get_clock_ns (vm_clock);
50     ticks = now - no->old_ticks;
51     bytes = muldiv64 (ticks, hw->info.bytes_per_second, get_ticks_per_sec ());
52     bytes = audio_MIN (bytes, INT_MAX);
53     samples = bytes >> hw->info.shift;
54 
55     no->old_ticks = now;
56     decr = audio_MIN (live, samples);
57     hw->rpos = (hw->rpos + decr) % hw->samples;
58     return decr;
59 }
60 
61 static int no_write (SWVoiceOut *sw, void *buf, int len)
62 {
63     return audio_pcm_sw_write (sw, buf, len);
64 }
65 
66 static int no_init_out (HWVoiceOut *hw, struct audsettings *as)
67 {
68     audio_pcm_init_info (&hw->info, as);
69     hw->samples = 1024;
70     return 0;
71 }
72 
73 static void no_fini_out (HWVoiceOut *hw)
74 {
75     (void) hw;
76 }
77 
78 static int no_ctl_out (HWVoiceOut *hw, int cmd, ...)
79 {
80     (void) hw;
81     (void) cmd;
82     return 0;
83 }
84 
85 static int no_init_in (HWVoiceIn *hw, struct audsettings *as)
86 {
87     audio_pcm_init_info (&hw->info, as);
88     hw->samples = 1024;
89     return 0;
90 }
91 
92 static void no_fini_in (HWVoiceIn *hw)
93 {
94     (void) hw;
95 }
96 
97 static int no_run_in (HWVoiceIn *hw)
98 {
99     NoVoiceIn *no = (NoVoiceIn *) hw;
100     int live = audio_pcm_hw_get_live_in (hw);
101     int dead = hw->samples - live;
102     int samples = 0;
103 
104     if (dead) {
105         int64_t now = qemu_get_clock_ns (vm_clock);
106         int64_t ticks = now - no->old_ticks;
107         int64_t bytes =
108             muldiv64 (ticks, hw->info.bytes_per_second, get_ticks_per_sec ());
109 
110         no->old_ticks = now;
111         bytes = audio_MIN (bytes, INT_MAX);
112         samples = bytes >> hw->info.shift;
113         samples = audio_MIN (samples, dead);
114     }
115     return samples;
116 }
117 
118 static int no_read (SWVoiceIn *sw, void *buf, int size)
119 {
120     /* use custom code here instead of audio_pcm_sw_read() to avoid
121      * useless resampling/mixing */
122     int samples = size >> sw->info.shift;
123     int total = sw->hw->total_samples_captured - sw->total_hw_samples_acquired;
124     int to_clear = audio_MIN (samples, total);
125     sw->total_hw_samples_acquired += total;
126     audio_pcm_info_clear_buf (&sw->info, buf, to_clear);
127     return to_clear << sw->info.shift;
128 }
129 
130 static int no_ctl_in (HWVoiceIn *hw, int cmd, ...)
131 {
132     (void) hw;
133     (void) cmd;
134     return 0;
135 }
136 
137 static void *no_audio_init (void)
138 {
139     return &no_audio_init;
140 }
141 
142 static void no_audio_fini (void *opaque)
143 {
144     (void) opaque;
145 }
146 
147 static struct audio_pcm_ops no_pcm_ops = {
148     .init_out = no_init_out,
149     .fini_out = no_fini_out,
150     .run_out  = no_run_out,
151     .write    = no_write,
152     .ctl_out  = no_ctl_out,
153 
154     .init_in  = no_init_in,
155     .fini_in  = no_fini_in,
156     .run_in   = no_run_in,
157     .read     = no_read,
158     .ctl_in   = no_ctl_in
159 };
160 
161 struct audio_driver no_audio_driver = {
162     .name           = "none",
163     .descr          = "Timer based audio emulation",
164     .options        = NULL,
165     .init           = no_audio_init,
166     .fini           = no_audio_fini,
167     .pcm_ops        = &no_pcm_ops,
168     .can_be_default = 1,
169     .max_voices_out = INT_MAX,
170     .max_voices_in  = INT_MAX,
171     .voice_size_out = sizeof (NoVoiceOut),
172     .voice_size_in  = sizeof (NoVoiceIn)
173 };
174